VATICAN CITY, JAN. 28, 2011 (Zenit.org).- Benedict XVI is encouraging the ongoing dialogue with the Eastern Orthodox Churches, which is currently focused on historical expressions of communion with the Catholic Church.

The Pope stated this today in an audience with members of the Joint International Commission for Theological Dialogue Between the Catholic Church and the Oriental Orthodox Churches.

He expressed gratitude for the work that began in 2003 as a joint initiative between Catholic and Orthodox leaders.

The first phase of this dialogue, which lasted through 2009, resulted in a joint document, "Nature, Constitution and Mission of the Church." This document outlined the shared principles of the Churches and identified issues requiring further discussion.

The Pontiff stated, "We can only be grateful that after almost fifteen hundred years of separation we still find agreement about the sacramental nature of the Church, about apostolic succession in priestly service and about the impelling need to bear witness to the Gospel of our Lord and Savior Jesus Christ in the world."

He noted that in this second phase of dialogue the commission is reflecting "from an historical perspective on the ways in which the Churches expressed their communion down the ages."

The Holy Father acknowledged, "During the meeting this week you are deepening your study of the communion and communication that existed between the Churches until the mid-fifth century of Christian history, as well as the role played by monasticism in the life of the early Church."

The will of Christ

He continued, "We must be confident that your theological reflection will lead our Churches not only to understand each other more deeply, but resolutely to continue our journey decisively towards the full communion to which we are called by the will of Christ."

Benedict XVI noted, "Many of you come from regions where Christian individuals and communities face trials and difficulties that are a cause of deep concern for us all."

"All Christians need to work together in mutual acceptance and trust in order to serve the cause of peace and justice," he affirmed.

The Pope concluded, "May the intercession and example of the many martyrs and saints, who have given courageous witness to Christ in all our Churches, sustain and strengthen you and your Christian communities."

The six ancient Eastern Orthodox Churches include the Armenian Apostolic Church, the Orthodox Coptic Patriarchate of Egypt, the Syro-Orthodox Patriarchate of Antioch, the Orthodox Church of Ethiopia, the Orthodox Church of Eritrea, and the Syro-Orthodox Church of Malankar.

These Churches separated from Rome after the Fourth Ecumenical Council of Chalcedon in 451, over controversy arising from the council"s adoption of the Christological terminology of two natures in one person.